# CVE-2025-27464: WinPVDrivers: Excessive permissions on user-exposed devices

> Unprivileged users can access XenBus driver facilities due to missing security descriptors, potentially leading to privilege escalation or security bypass.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jul 2026
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-jmgg-9rvf-m69w

## What is CVE-2025-27464?

CVE-2025-27464 is a critical missing authorization vulnerability in Xen Windows PV drivers, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The Windows PV drivers expose various facilities to userspace. Several of these have no security descriptor, and are therefore fully accessible to unprivileged users. These are: 1. XenCons, CVE-2025-27462 2. XenIface, CVE-2025-27463 3. XenBus, CVE-2025-27464

Weakness: CWE-276 (Incorrect Default Permissions)

## Which versions are affected by CVE-2025-27464?


## How do I fix CVE-2025-27464?

Apply the vendor's patch.

## Is CVE-2025-27464 being exploited?

There is no known exploitation of CVE-2025-27464 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-27464 and fix it if it is affected.

What it is: CVE-2025-27464 is a critical missing authorization vulnerability in Xen Windows PV drivers, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-27464 in the wild and no public exploit code.

Affected product: Xen Windows PV drivers. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-27464/ (Markdown: https://insights.sbomify.com/CVE-2025-27464/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27464
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27464
- OSV: https://osv.dev/vulnerability/CVE-2025-27464

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-27464/
Summaries are generated and may contain mistakes; the official description above is the record.